May 112013

Reading punched tape

Rapid prototyping tools are great for quick hacks, but their real power lies in their ability to allow you to quickly iterate and refine a design. Earlier this week I hacked together a primitive nine-channel punched paper tape reader, but it had a number of limitations: the LEDs that I was using to read the bits were noisy and slow, the materials used didn’t mask the light well enough, the tape wasn’t mechanically aligned well, the electronics were a mess and the entire mechanism was difficult to use. This Friday, I decided to do what my third-grade teacher would tell me to do every time I half-assed something: go back and do it right.

Tape reader parts

This time I used proper phototransistors and IR LEDs I scrounged up around the space (thanks, Miria and Raphael!). Because they’re 5mm in diameter (and the spacing between channels is only 2.54mm), I had to come up with a new sensor packing. This one reads bits from four separate columns over a space of five columns, requiring an internal buffer of five columns to reconstruct a single column of data. Even so, the spacing was tight, and I had to sand down the flanges of the phototransistors and LEDs to make everything fit. I milled simple PCBs for both sides to keep things nice and neat, and used a small surface-mount potentiometer to limit the current to the LEDs in case the paper wasn’t thick enough to block enough light. The light mask is made of black acetal this time, and the spacers include runners to help keep the tape straight. There’s still no automatic feed mechanism, but we now have a reader that’s fast and reliable enough to read tapes in earnest.

The updated code, mechanical drawings, and PCB designs are all up on Github. There are still a few tweaks we’d want if we were going to scan more tapes, but this version works very well. Now we just have to figure out what to do with all these PDP-8 binaries. Any ideas?


(Note to time-travelling computer conservators: in the past/future, please do not store your paper tapes in damp basements. These programs are stinky. The Fortran compiler, in particular, is exceptionally foul. Yours truly, phooky.)

 Posted by at 6:17 pm
May 102013

SpaceInvaderNails-1Ever wanted to trick your nails out with a paint-job worthy of notice?  This is how… and no need to pay a salon $50 for the glory.  We’ll teach you how on Saturday (5:30-8:30pm) after our Laser Class, using templates stamps and other techniques.  We’ll have a small selection of polishes, so if you’re after a specific color combo you may want to bring your own. Tickets still available here– be prepared to come with a base-coat or to add one while you’re there.  GUYS WELCOME! (Remember you can also paint your toes).

May 092013

Trammell came across a cache of punched paper tape recently. My immediate impulse was to create the most primitive tape reader possible. Thusly:

The rig is composed of a Teensy++ 2.0, eighteen red LEDs, eighteen resistors, and a few bits of laser-cut plastic. LEDs are used to both illuminate the paper and sense the holes. The sensor design is based on the classic Arduino LED sensing code. It’s not very reliable, but it’s a fun afternoon proof-of-concept.

If you’re interested, the code and design files are up on github.

 Posted by at 8:54 pm
May 022013

Some of you may remember the last installment in our on-going series on computational necromancy, where I made a call out to the internet to help revive my bit-rotted copy of the once-lost Cray Operating System. An amazing programmer named Andras has answered that call in a way I would have never thought possible – he not only used his kung-fu to recover an intact copy of COS from my disk image, he wrote a simulator for an entire data center worth of Cray X-MP equipment and got it to boot!


If anyone has been sitting on Cray-1 or Cray X-MP software (or you just have some idea of how to use COS!) for the last 30 or so years, now is the time to come out of the woodwork! Get in touch with me or Andras and we’ll make it happen.

Go, download the simulator and have your own simulated 1980′s data-center! Or just read his incredible write-up on his progress so far!

Apr 232013

A year ago Super Awesome Sylvia demoed MarioChron for the Adafruit MonoChron dekstop clock kit. It’s really neat — once per minute Mario hits the box and receives a coin, so his score is equal to the time. Now thanks to the GPL license on the code, you can carry it on your wrist with the port of MarioChron to the Pebble Smart Watch:
MarioChron, Pebble edition

You can install the prebuilt mario.pbw binary and the source is available for further hacking. Here’s a short video of Mario’s coin collecting action (the jump height has since been fixed in the source code).

The code is a straightforward port that reuses almost all of the original logic. The only change is to rearrange the screen slightly from the MonoChron’s 128×64 LCD to the Pebble’s 168×144. This involved translating the glcdClearDot() and glcdSetDot() calls to 2×2 rectangles using the Pebble’s graphics_fill_rect() functions. Unfortunately the e-paper display on the Pebble is designed for mostly static images, and updating it at 10 Hz for the animation draws far more power than a once-per-minute clock face. This means that this watch face consumes lots of power and the Pebble only lasts part of one day instead of an entire week. Perhaps optimizing the redraws instead of redrawing the entire screen would let it last longer.

Want to learn how to write your own watches for the Pebble? Sign up for the May 18 Pebble programming class at NYCR or come to the hackathon after!

 Posted by at 8:46 pm
Apr 162013

Pebble Polar Map

What time is it? It’s time to #MakeAwesomeHappen and learn to program the new Pebble Smart Watch! We’ll be teaching a three hour class on 18 May on how to write custom watch faces that work with the official Pebble SDK. The programming environment is low-level C, with no memory protection, and no emulator nor a debugger, so you’ll need to be fairly comfortable with writing embedded code or at least not afraid to debug with printf()*. If you’ve programmed a device like an Arduino you should be ok with the class. Tickets for the class are on sale for $125. The hackathon afterwards is free!

Pebble wordsquare watch

If you haven’t heard of it, Pebble was the wildly successfull kickstarter project that pre-sold over 80,000 watches. The watch has a 144×168 transreflective e-paper display, an ARM M3, Bluetooth, an accelerometer and lots of potential. MyPebbleFaces has a few hundred ideas for fun projects and many people have already programmed their dream watch faces.

Pebble class at NYC Resistor

After the class, we’ll be holding an all-night hackathon to write some new watches. Developers from Team Pebble will be here to hack with us and help answer any deep questions about the API. The hackathon is open to everyone with a Pebble and is a great chance to meet other wearable wrist-watch computing enthusiasts in New York. If you don’t have your Pebble yet or don’t want to risk your prized wristwatch, we’ll have a limited quantity of factory seconds that might not be waterproof, might have glue bubbles, or discoloured bezels or other QC issues available for $75. Tickets for the class and hackable watches are available here!

 Posted by at 9:28 pm
Apr 162013


Get that Club Mate cold and those soldering irons hot because it’s time for another Interactive Show! We’re putting out the call to hackers around the globe to come show your stuff at our annual party.

This years theme: Digital Archeology. Think old technology with a new purpose, or new technology retropackaged to look vintage. As always anything interactive applies so use your imagination.

We’re targeting mid-June so there’s plenty of time to get involved. If you’re interested in participating drop us a line.

Mar 312013

So, once in a while, I wake up feverish in the middle of the night, screaming “CLAMPS! I NEED MORE CLAMPS!” Oh, you too, huh?

It's clamps.

It’s your lucky day! Or rather, this coming Sunday, April 7th is your lucky day, when NYCR and our good friends at the Industry City Distillery will be having our first-ever garage sale. We’ll be selling all kinds of hardware oddities, including:

  • Clamps!
  • Hand tools!
  • Power tools!
  • Strange, unidentifiable tools meant for neither hand nor eye!
  • Microscopes! Boroscopes!
  • Audio equipment! Video equipment! Audiovisual equipment!
  • Files! Floppy diskettes! Raw steel! Cooked steel!
  • A vertical mill! (U-buy, U-move!)
  • Clamps!
  • Files!
  • Electronic bits! Non-electronic bits!
  • More VHS recorders than you’re prepared to buy!
  • aaannnddd moooooorrrreeee!!!

We’ll be having the sale in beautiful Industry City, Brooklyn, in association with the Industry City Distillery, manufacturers of incredible spirits. Come by to buy! Come by to browse! Come by to meet amazing people!

Files, on floppy and off!

The sale starts at 11:30 AM, Sunday, April 7th and continues until sunset, at which point we’ll just start calling it a party. The address is 33 35th Street, Brooklyn, NY, just two blocks downhill from the 36th Street Station on the D, N, and R trains. It’s just one stop on the N train from NYCR.

See y’all Sunday!

(We’re not kidding about the mill.)
It's a mill.

 Posted by at 10:38 pm
Mar 202013

LCD backlight teardown

These are seven layers of a backlight from an old laptop LCD. The amount of optical engineering required to produce a nice, even glow from an edge-lit panel is impressive.

Backlight filters

(Be careful if you’re taking one apart yourself– until recently many LCDs were backlit by CCFLs, which contain a small amount of mercury and need to be disposed of properly.)

 Posted by at 5:31 pm
Feb 282013

Ranjit Bhatnagar, Nick Vermeer and William Ward of NYC Resistor have teamed up with Brooklyn Ballet to create a mixed-medium performance involving captivating dancers and realtime stylized visualization of their choreography.

Performances Feb 28, March 1, 2, 8 & 9 at 8PM, with matinee performances March 3rd and 10th at 4PM for the early-to-bed crew.

Actors Fund Arts Center, 160 Schemerhorn, a 10 minute walk from NYC Resistor!

$25 ($15 for you poor students or distinguished seniors!) tickets here!



(Tools used will be discussed later, I’m going to get some sleep. — wwward)

 Posted by at 12:41 am